Abstract

Formic acid is the simplest of the homologous series of alkyl carboxylic acids. It is a liquid boiling at 101C with an intense pungent smell. It forms hydrogen-bonded dimers in the gas phase and polymeric chains in the solid state.

Many of the chemical properties of formic acid are broadly similar to those of other aliphatic carboxylic acids, but with the differences commonly found in the first member of a homologous series. It is, for example, a stronger acid than any of the higher homologues. Formic acid can decompose either to CO and H₂O or CO₂] and H₂.

Formic acid is manufactured industrially as a medium-tonnage commodity (world capacity ca 330,000 t/yr). It is produced by three different processes: from formate salts, by liquid-phase oxidation of hydrocarbons, and by carbonylation of methanol to give methyl formate, followed by hydrolysis. The last of these is the most important industrially.

Formic acid is shipped in concentrations of 85-;mt 99%. Appropriate precautions must be followed in shipping and handling of this corrosive material.

In Europe formic acid's largest use is as a silage addition whereas in the United States this application scarcely exists, and formic acid's main U.S. markets are in the textile and rubber industries and as a chemical intermediate.